I'm an actual pedophile (the evil kind).

I actually like little girls sexually. I want to fuck a little girl. I want to touch her. Put my penis in her mouth. Molest her. Spank her. Be mean to her and then comfort her so she gets confused.

If this is unnatural, why was I born this way? Why do humans have this desire if it's so evil?

Because, it used to be good in past times when there was no civilization, and now is bad. Like rape, for example. Or it is an anomaly, and a small meme among small amounts of people.